Discharge Fluctuation Effect on Meandering River Bed Evolution

This research was based on some considerations: first discharge fluctuation argued that none rivers with constant discharge and second meandering river bed evolution with considering that none of rivers in a steady state without bed change. This research developed to get formulation the relationship between fluctuations discharge with the evolution of the bottom of river considering discharge, parameter rivers and parameter sediment. In the span of daily discharge data 1997-2011 and cross section monitoring annual results 1997-2011 evolution of bottom of a river subjects obtained: Formula 1 is the relationship between discharge fluctuations with rate of sedimentation (S) and Formula 2 is the relationship between discharge fluctuations with rate of erosion (E). Thus formula have higher prediction accuracy than other published formulas and it is applicable to predict Brantas River bed evolution approximate with the real conditions. Further analysis from the output KUN-QArSHOV formula produces: Erosion equation ΔS = 25,167e^{0,0034 ΔQ} , on constant discharge, sedimentation value occur is 25.167.10^-5 meter. Sedimentation equation ΔE = 8,3455e^{0,0075 ΔQ} , on constant discharge, erosion value occure is 8.3455.10^-5 meter. Critical point between sedimentation and erosion happened on discharge between 269 m³/second and 270 m³/second.